The nervous system/ neurons/ nerves
The answer you are looking for is “organ system”
Answer:
Nucleus: an organelle that is in most eukaryotic cells that contains genetic material for the organism
Ribosome: particles consisting of RNA and proteins that perform protein synthesis
Endoplasmic Reticulum: a network of membranous tubules within the cytoplasm that has ribosomes connected to them, involved in protein and lipid synthesis
Golgi Apparatus: a complex of vesicles and folded membranes within the cytoplasm, involved in secretion and intracellular transport
I hope this helps you!
It tells us how they walked and a rough size estimate